I recently heard of this king, known as Charles the Beloved then later the Mad. Do we know what condition he suffered from that caused these outbursts of ‘madness’? When did they start, and why so randomly? My initial thought is possibly some kind of triggerable schizophrenia, but I’m by no stretch of the imagination any sort of psychologist.
Thanks in advance.
I don't want to be that guy, but, because this is r/AskHistorians, I feel I should give the historian answer, so I apologize in advance for the tiresome bit.
We don't know what caused Charles VI's illness. There are reports that the first known onset coincided with the attempt on the life of Olivier de Clisson in 1392, but, unless additional sources are discovered, that is as much as we can know. R. C. Famiglietti's Royal Intrigue: Crisis at the Court of Charles VI, 1392–1420 (New York: AMS Press, 1986) is as good a source as you're going to find for specific information about Charles VI in English.
There are a number of hereditary and non-hereditary illnesses affiliated with European royal mental illness, with prophyria probably being the most famous because of it's connection with George III of the United Kingdom. The problem with someone like Charles VI is that he lived from 1368 to 1422, which, while nowhere near as scientifically incompetent as is popularly believed, was not a period known for recording symptoms in documents intended for long-term preservation (chronicles, etc.). Thus, any indication of the identifying features of a given illness (other than dramatic psychosis) have, unfortunately, been lost to history. It is, therefore, not only difficult, but irresponsible for an historian (even if they posses degrees in psychology or psychiatry) to do anything more than speculate in the most ethereal fashion.
That being said, there is nothing wrong with conducting those ethereal speculations with a solid understanding of the symptoms and biochemistry of the candidate ailments, but I am afraid I am not the person to ask in this instance (though my father is a retired neuropsychologist, and I can ask his opinion the next time I talk to him if you're really interested).
If you're interested in royal maladies, generally, might I suggest you take a look at Alan R. Rushton's Royal Maladies: Inherited Diseases in the Ruling Houses of Europe (Victoria, British Columbia: Trafford, 2008)? If I'm honest, this kind of book often gives me pause, but, based on my brief reading, it seems like a thorough and authoritative study. It would certainly make excellent reading for personal interest on the subject, and there is a short section dedicated to Charles VI.
I hope this helps.